Bobbin winding machine

ABSTRACT

A bobbin winding machine with a plurality of winding stations which are arranged along a bobbin winding spindle for winding a plurality of threads into bobbins is described. The winding stations are assigned a traversing device which has a flyer traversing unit for each winding station. The flyer traversing units are driven jointly and for this purpose have in each case a drive wheel which is coupled to a driven driving wheel via a toothed belt. The toothed belt is coupled to the toothed drive wheels and to the toothed driving wheel via a toothed profile side.

The invention relates to a bobbin winding machine having a plurality ofwinding stations according to the precharacterizing clause of Claim 1.

A generic bobbin winding machine is known from EP 0 965 554 A2.

Bobbin winding machines of this type are used in the production ofsynthetic threads for the purpose of winding the threads into bobbins.In this case, depending on the process and type of thread, high threadrunning speeds are generated which may lie in the range above 6000m/min. Since in the melt-spinning process the threads are extruded,treated and guided within a spinning position as a thread group, thewinding of the threads and the bobbins likewise takes place in parallelnext to one another. For this purpose, the known bobbin winding machinehas a projecting bobbin winding spindle on which a plurality of windingstations arranged in a distributed manner are formed. So that thethreads can be wound into bobbins in a crosswinding, a traversing deviceis provided which has a flyer traversing unit for each winding station.Flyer traversing units of this type are suitable, in particular, forbeing able to guide the respective thread to and fro in the windingstation at high speeds. For this purpose, the flyer traversing unitshave two contradirectionally rotating flyer rotors which guide thethread alternately to and fro. The flyer traversing units are drivensynchronously, the torque of an electric motor being transmitted via abelt drive to each of the flyer traversing units.

In order in each of the winding stations to bring about a uniform bobbinbuild-up when the threads are being wound, torque transmission takesplace, free of slip, by means of a toothed belt. The toothed belt hastwo opposite profile sides, on which a toothing having a multiplicity ofprojecting belt teeth is formed. The toothed belt is guided within thebelt drive via at least one driving wheel and a plurality of drivewheels, the driving wheel and drive wheels being in engagement with theopposite profile sides of the toothed belt. Thus, accuracy of positionwhen the flyer traversing units are being driven can be determinedsolely by one of the profile sides of the toothed belt, the said profileside cooperating with the drive wheels. By contrast, the starting loadand braking load generated via the driving wheel are absorbed by theopposite profile side which is usually designed to be morewear-resistant. However, such alternating meshing on the toothed beltcauses vibrations to occur on the toothed belt, this, as what is knownas the polygon effect, adversely influencing the uniformity oftraversing in the winding stations. The polygon effect is additionallypromoted also by the unequal manufacturing tolerances of the profilesides.

The object of the invention, therefore, is to provide a bobbin windingmachine of the generic type, in which the flyer traversing units can bedriven with high uniformity in the winding stations.

This object is achieved, according to the invention, in that the toothedbelt is coupled to the toothed drive wheels and to the toothed drivingwheel via a toothed profile side.

Advantageous developments of the invention are defined by the featuresand feature combinations of the respective subclaims.

It became apparent, surprisingly, that the joint engagement of thedriving wheel with the drive wheels on one toothed profile side of thetoothed belt does not have an adverse effect upon the positioningaccuracy for driving the flyer rotors. By an appropriate choice ofmaterial, the wear phenomena generated by the driving wheel on thetoothed profile side of the toothed belt can be limited in such a waythat, even if there was a plurality of drive wheels, no phasedifferences arise between the driven flyer rotors of the flyertraversing units. If all toothed wheels contact the toothed belt on oneside only, the other side of the toothed belt may be toothed as well orflat.

So that sufficient looping of the toothed belt on the drive wheels canbe ensured when the driving wheel and the drive wheels arranged next toone another have the same direction of rotation, there is provision,furthermore, whereby one of a plurality of deflecting rollers isarranged between adjacent drive wheels, and whereby the deflectingrollers guide the toothed belt on an opposite flat side. Consequently,on each of the drive wheels, the toothed belt can be driven via aplurality of intermeshing belt teeth. Each of the drive wheels cantherefore be driven codirectionally via the toothed belt with reliablepositioning.

Belt guidance between the drive wheels and the driving wheel can beimproved further in that the deflecting rollers have in each case aguide casing with one or more continuous guide grooves, and in that thetoothed belt can be guided on the flat side by the guide casing with orwithout an endless longitudinal web. Transverse guidance of the toothedbelt is thereby generated and prevents the toothed belt from moving upand down. In particular, what is achieved thereby is that the belt teethcan roll on the drive wheels under identical geometric conditions.

To receive the flyer traversing units, these are preferably arrangedtogether with the drive wheels and the driving wheel on a plate-shapedcarrier which is held movably on a machine stand. As a result of themovability of the plate-shaped carrier, a traversing distance formedbetween the flyer rotors and a following contact roller can be keptconstant even with growing bobbin diameters and with a movable pressureroller.

For the decoupling of the traversing device, preferably a plurality ofdamping elements are provided between the traversing carrier and themachine stand, so that the vibrations generated by the drive of thebobbin winding spindles and the winding of the bobbins are nottransmitted to the drive system of the traversing device.

To transmit and convert the rotational movement generated by the drivewheel, each of the flyer traversing units has a power divider which iscoupled to the drive wheel and which drives two rotatable flyer rotorscontradirectionally. In this case, adjacent flyer rotors can be drivencodirectionally or contradirectionally.

In order to obtain overlapping of the rotatable flyer rotors of adjacentflyer traversing units when the drive wheels are driven codirectionally,the bobbin winding machine is preferably designed in such a way that thepower dividers are formed alternately by one of two types of gear whichgenerate an opposite direction of rotation on the flyer rotors.

In addition to wear resistance, moreover, the generation of noise can beinfluenced positively by the development of the invention in which theflat side of the toothed belt carries a damping textile ply, the basicmaterial of the toothed belt being formed from a polyurethane, and aplurality of steel cords being embedded in the basic material.High-performance materials of this type have proved especiallyappropriate for driving a plurality of flyer traversing units in thebobbin winding machine reliably. Thus, ten, twelve or even more flyertraversing units of the traversing device can be driven reliably via onebelt drive in the bobbin winding machine.

In the traversing and winding of the threads into bobbins, it must beremembered, furthermore, that rapid frequency changes within thetraversing operation are necessary in order to avoid pattern-breakingwindings which appreciably disrupt the bobbin build-up. It was shown,then, that the spacing of the belt teeth influences an excitingfrequency of the toothed belt. In order to avoid superposed resonancesbetween the traversing frequency and an exciting frequency of thetoothed belt, the development of the invention is especiallyadvantageous in which the profile side of the toothed belt has amultiplicity of belt teeth with a spacing in the range of between 4 mmand 5 mm. It became apparent, surprisingly, that a spacing in the rangeof between 4 mm and 5 mm has an especially beneficial effect upon thedrive of the flyer traversing units and the laying of the threads toform the bobbins.

An exemplary embodiment of the bobbin winding machine according to theinvention is described in more detail below for the further explanationof the invention. For this purpose, the following figures are appendedto the description.

In the Drawings:

FIG. 1 illustrates diagrammatically a front view of an exemplaryembodiment of the bobbin winding machine according to the invention

FIG. 2 illustrates diagrammatically a top view of the exemplaryembodiment from FIG. 1

FIG. 3 illustrates diagrammatically a cross-sectional view of anexemplary embodiment of a deflecting roller

FIG. 4 illustrates diagrammatically a cross-sectional view of a furtherexemplary embodiment of a deflecting roller

FIG. 5 illustrates diagrammatically a partial view of the toothed beltof the exemplary embodiment according to FIGS. 1 and 2

FIG. 6 illustrates diagrammatically a cross-sectional view of thetoothed belt from FIG. 5.

FIGS. 1 and 2 illustrate an exemplary embodiment of the bobbin windingmachine according to the invention in various views. FIG. 1 showsdiagrammatically a front view and FIG. 2 diagrammatically a top view ofthe exemplary embodiment. In so far as there is no express referencemade to one of the figures, the following description applies to bothfigures.

The illustrated exemplary embodiment of the bobbin winding machineaccording to the invention is conventionally used in a productionprocess for synthetic threads in a melt-spinning plant for winding agroup of threads which are extruded, drafted and treated as a threadgroup and are delivered to the bobbin winding machine. In the bobbinwinding machine, one of a plurality of winding stations is formed foreach of the threads.

As may be gathered from the illustration in FIG. 2, the exemplaryembodiment has altogether four winding stations 5.1, 5.2, 5.3 and 5.4 inorder in each of the winding stations 5.1 to 5.4 to wind a thread intoin each case a bobbin 6.1 to 6.4. For this purpose, the bobbins 6.1 to6.4 are held next to one another on a projecting bobbin winding spindle2. The bobbin winding spindle 2 is driven in such a way that the threadsare wound on the bobbins 6.1 to 6.4 at an essentially constant windingspeed. In order to wind a thread into a bobbin in each of the windingstations 5.1 to 5.4, the bobbin winding spindle 2 is preceded by atraversing device 7. The traversing device 7 has for each of the windingstations 5.1 to 5.4 in each case a flyer traversing unit 8.1 to 8.4. Theflyer traversing units 8.1 to 8.4 are driven as a drive group by anelectric motor 10. For the transmission of torque, the electric motor 10is coupled to the flyer traversing units 8.1 to 8.4 via a belt drive 9.For this purpose, the belt drive 9 has for each flyer traversing unit8.1 to 8.4 in each case a drive wheel 11.1 to 11.4 which are coupled toa driving wheel 14 via a toothed belt 12. The driving wheel 14 is drivendirectly via the electric motor 10, the driving wheel 14 and the drivewheels 11.1 to 11.4 rotating codirectionally by means of the toothedbelt 12. The toothed belt 12 has on one profile side a multiplicity ofbelt teeth which engage into toothings of the driving wheel 14 andtoothings of the drive wheels 11.1 to 11.4.

In order to obtain sufficient looping on the drive wheels 11.1 to 11.4in order to drive the flyer traversing units 8.1 to 8.4, in each caseone of a plurality of deflecting rollers are arranged between adjacentdrive wheels. Thus, the deflecting roller 16.1 is arranged between thedrive wheels 11.1 and 11.2, the deflecting roller 16.2 between the drivewheels 11.2 and 11.3 and the deflecting roller 16.3 between the drivewheels 11.3 and 11.4. The deflecting rollers 16.1, 16.2 and 16.3 areassigned to a flat side of the toothed belt 12. Thus, the toothed belt12 can be guided with alternating looping between the drive wheels 11.1to 11.4 and the deflecting rollers 16.1 to 16.3.

The return of the toothed belt 9 takes place via two guide wheels 15.1and 15.2 which have a toothing and which cooperate with the profile sideof the toothed belt 12.

As may be gathered from the illustrations in FIGS. 1 and 2, each of theflyer traversing units 8.1 to 8.4 has a power divider 13 which iscoupled directly to one of the drive wheels 11.1 to 11.4. The windingstation 5.4 having the flyer traversing unit 8.4 is showndiagrammatically in FIG. 1. Each of the flying units 8.1 to 8.4 and eachof the following winding stations 5.1 to 5.4 are constructedidentically, and therefore the winding station 5.4 having the flyertraversing unit 8.4 is explained by way of example by means of theillustration in FIG. 1.

A first flyer rotor 17.1 having a first flyer set and a second flyerrotor 17.2 having a second flyer set are driven contradirectionally bythe power divider 13. The flyers of the flyer rotors 17.1 and 17.2 areassigned a guide ruler 26, at which guide edge a thread 31 can be guidedto and fro via the two flyer sets.

In order to obtain a compact arrangement of the flyer traversing units8.1 to 8.4 next to one another, the flyer sets of the flyer rotors 17.1and 17.2 are designed in such a way that adjacent flyer rotors ofadjacent flyer traversing devices 8.1 and 8.2 mesh with one another. Forthis purpose, the power divider 13 is preferably formed by two types ofgear which generate an opposite direction of rotation on the rotorflyers. Thus, the power divider 13 can be designed as a left-handed gearor right-handed gear.

Basically, however, there is also the possibility that the powerdividers 13 are designed identically, so that each of the driven flyerrotors 17.1 and 17.2 of the flyer traversing units 8.1 to 8.4 can bedriven identically in the same direction of rotation.

The flyer traversing unit 8.4 is arranged on a plate-shaped traversingcarrier 21 which extends over the entire traversing apparatus 7 andcarries the belt drive 9 and also the other flyer traversing units 8.1to 8.3. In this exemplary embodiment, the traversing carrier 21 issupported on pivoting arms 19 which are held pivotably in a machinestand 1 via a plurality of damping elements 32 and which carry apressure roller 18 at their free ends. The pressure roller 18 is mountedrotatably on the pivoting arms 19 and bears against the surface of thebobbins 6.1 to 6.4 during the winding operation.

The traversing carrier 21 is held next to the pressure roller 18 by thepivoting arm 19, so that the traversing carrier 21 is guided movably,together with the pivoting arm 19, on the machine stand 1. A traversingdistance formed between the guide rulers 26 and the pressure roller 18is consequently kept constant independently of the respective positionof the pivoting arm 19. To an extent, in any position of the pressureroller 18, the threads can be guided to and fro with identical draglengths by the flyer traversing units 8.1 to 8.4.

As will be gathered from the illustration in FIG. 1, a spindle carrier 4in the machine stand 1 is designed as a bobbin winding turret, on whicha second bobbin winding spindle 3 is held in a projecting manner. Eachof the bobbin winding spindles 2 and 3 can be driven independently ofone another, the spindle carrier 4 likewise being assigned a drive. Inthis exemplary embodiment, the drives are not illustrated. To wind thethreads on the bobbins 6.1 to 6.4, the bobbin winding spindle 2 isguided by the movement of the spindle carrier 4. After the end of thebobbin winding operation and the completion of the bobbins 6.1 to 6.4,the bobbin winding spindle 2 is guided out of the winding region into achanging region and the bobbin winding spindles 3 are guided out of thechanging region into the winding region. Continuous winding of thethreads is to that extent possible.

When the threads are being wound into the bobbins 6.1 to 6.4, they areguided to and fro at a stipulated traversing frequency by the flyertraversing units 8.1 to 8.4. The traversing frequency of the flyertraversing units 8.1 to 8.4 is determined by the electric motor 10 andis transferred from the driving wheel 14 to the drive wheels 11.1 to11.4 via the toothed belt 12. In this case, it is customary for thetraversing frequency to be varied during the winding of the threads inorder to avoid what are known as pattern-breaking windings. Thesechanges are likewise carried out directly via the electric motor 10 andthe belt drive 9. High dynamic loads thus occur on the toothed belt 12and are accompanied by speed changes. For the stability of the beltdrive 9, the toothed belt is preferably guided positively on thecircumference of the deflecting rollers 16.

FIG. 3 illustrates an exemplary embodiment of a deflecting roller 16.1diagrammatically in a cross-sectional view. The deflecting roller 16.1has a guide casing 28 which is mounted rotatably on a shaft 33. Theguide casing 28 has on the circumference a guide groove 29 whichreceives a flat side 23 of the toothed belt 12. Opposite to the flatside 23, the toothed belt has a profile side 27 having the belt teeth22.

Alternatively, however, there is also the possibility of arranging oneor more longitudinal webs on the flat side 23 of the toothed belt 12. Anexemplary embodiment of this kind is illustrated in FIG. 4. FIG. 4 showsa deflecting roller 16.1 diagrammatically in a cross section. In thisdeflecting roller 16.1, the guide casing 28 has two guide grooves 29running parallel. The guide grooves 29 are designed in such a way thattwo longitudinal webs 30 on the flat side 23 of the toothed belt 12 canbe guided therein. Reliable and quiet running of the toothed belt 12 isconsequently achieved particularly in the region of the drive wheels11.1 to 11.4.

The design of the toothed belt 12 of the belt drive 9 can be explainedparticularly by means of the illustrations belonging to FIGS. 5 and 6.

FIG. 5 illustrates a partial view of the toothed belt 12 and FIG. 6 across-sectional view of the toothed belt 12. In so far as there is noexpress reference made to one of the figures, the following descriptionapplies to both figures.

The toothed belt 12 has a profile side 27 and an opposite flat side 23.A multiplicity of belt teeth 22 are formed on the profile side 27. Thetoothed belt 12 is designed as an endless belt. The belt teeth 22integrally formed on the profile side have in each case the form of aparabola with completely filled tooth tips. The parabolic form of thebelt teeth 22 is essentially identical to the known high-performanceprofiles bearing the designation RPP. The spacing, which is depicted inFIG. 5 by reference letter T, designates in this case the distancebetween adjacent belt teeth 22 on the profile side 27. In light of theuse and function of the toothed belt 12 in the traversing device 7, thespacing T is set at a value in the range of between 4 mm and 5 mm. Byvirtue of this spacing T, disturbing resonance phenomena, which may havea disruptive effect upon the winding of the threads and the variedtraversing frequencies, are advantageously avoided.

The construction of the toothed belt 12 may be gathered essentially fromthe illustration in FIG. 6. The toothed belt 12 is formed from athermoplastic basic material, preferably a polyurethane. A plurality ofsteel cords 24 are embedded next to one another within the basicmaterial. A textile ply 25 is provided in each case on the outer flatside 23 and on the outer profile side 27 and covers the surface of thetoothed belt 12. Textile plies 25 of this type have an especiallyadvantageous effect on noise reduction. Moreover, the high coefficientsof friction of the basic material can consequently be reduced.

The thermoplastic basic material, when used in the bobbin windingmachine, has proved appropriate, in particular, with respect to theconditions prevailing in the surroundings. Thus, the volatileconstituents, such as, for example, preparation residues, which aredetached from the threads cannot lead to any adverse chemical reactionson the toothed belt 12. Premature wear and abrasion due to chemicalattack by preparation residues has advantageously been avoidable.

The steel cords 24 illustrated in FIG. 6 within the basic materials areone example of strand material for increasing the strength. Other strandmaterials, such as, for example, carbon fibres, are basically alsopossible.

The drive wheels 11.1 to 11.4 illustrated in FIGS. 1 and 2 and also thedriving wheel 14 and guide wheels 15.1 and 15.2 are preferably designedwith a circular tooth profile for the belt drive 9. Profiles of thistype, which are also known, for example, under the reference letters HDTas high-performance profiles, have, together with the parabolic profilechosen on the belt, a beneficial effect upon the running behaviour andthe tooth flank wear and also on the rolling behaviour of the teeth. Thefly traversing units 8.1 to 8.4 of the traversing device 7 canconsequently be driven reliably and free of slip.

In particular, the introduction of a torque, via the driving wheel 14and the transmission of the torque to the drive wheels 11.1 to 11.4 canadvantageously be carried out via the profile side 27 of the toothedbelt 12. The loads generated by the driving wheel 14 during thestarting, changing and braking of the traversing frequency do not havean adverse effect upon the positioning accuracy of the phase positionsof the flyer traversing units. High uniformity in the winding of thethreads in each of the winding stations 5.1 to 5.4 can consequently beachieved.

LIST OF REFERENCE SIGNS

-   1 Machine stand-   2 Bobbin winding spindle-   3 Bobbin winding spindle-   4 Spindle carrier-   5.1, 5.2, 5.3, 5.4 Winding stations-   6.1, 6.2, 6.3, 6.4 Bobbins-   7 Traversing device-   8.1, 8.2, 8.3, 8.4 Flyer traversing units-   9 Belt drive-   10 Electric motor-   11.1 . . . 11.4 Drive wheel-   12 Toothed belt-   13 Power divider-   14 Driving wheel-   15.1, 15.2 Guide wheel-   16.1, 16.2, 16.3 Deflecting roller-   17.1, 17.2 Flyer rotor-   18 Pressure roller-   19 Pivoting arm-   20 Bobbin winding tube-   21 Traversing carrier-   22 Belt tooth-   23 Flat side-   24 Steel cord-   25 Textile ply-   26 Guide ruler-   27 Profile side-   28 Guide casing-   29 Guide groove-   30 Longitudinal web-   31 Thread-   32 Damping element-   33 Shaft

1. Bobbin winding machine with a plurality of winding stations which arearranged next to one another along a bobbin winding spindle and wind aplurality of threads in parallel into a plurality of bobbins, and with atraversing device which has a flyer traversing unit for each windingstation, the flyer traversing units being assigned a plurality of drivewheels which are arranged next to one another and which are coupled viaa toothed belt to a driven toothed driving wheel for driving the flyertraversing units, wherein the toothed belt is coupled to the tootheddrive wheels and to the toothed driving wheel via a toothed profileside.
 2. Bobbin winding machine according to claim 1, wherein one of aplurality of deflecting rollers is arranged between adjacent drivewheels, and in that wherein the deflecting rollers guide the toothedbelt on an opposite flat side.
 3. Bobbin winding machine according toclaim 2, wherein the deflecting rollers have in each case a guide casingwith one or more continuous guide grooves, and wherein the toothed beltcan be guided on the flat side by the guide casing with or without anendless longitudinal web.
 4. Bobbin winding machine according to claim1, wherein the flyer traversing units, the drive wheels and the drivingwheel are arranged on a plate-shaped traversing carrier which is heldmoveably in a machine stand.
 5. Bobbin winding machine according toclaim 4, wherein a plurality of damping elements are arranged betweenthe traversing carrier and the machine stand.
 6. Bobbin winding machineaccording to claim 1, wherein each of the flyer traversing units has twocontradirectionally rotatable flyer rotors and a power divider which iscoupled to one of the drive wheels wheel.
 7. Bobbin winding machineaccording to claim 6, wherein the power dividers are formed selectivelyby one of two types of gear which generate an opposite direction ofrotation on the flyer rotors.
 8. Bobbin winding machine according toclaim 3, wherein the flat side of the toothed belt carries a dampingtextile ply, a basic material of the toothed belt being formed from apolyurethane, and a plurality of steel cords being embedded in the basicmaterial.
 9. Bobbin winding machine according to claim 8, wherein theprofile side of the toothed belt has a multiplicity of belt teeth with aspacing (T) in the range of 4 mm to 5 mm.
 10. Bobbin winding machineaccording to claim 1, wherein a flat side of the toothed belt carries adamping textile ply, a basic material of the toothed belt being formedfrom a polyurethane, and a plurality of steel cords being embedded inthe basic material.
 11. Bobbin winding machine according to claim 10,wherein the profile side of the toothed belt has a multiplicity of beltteeth with a spacing (T) in the range of 4 mm to 5 mm.